FR3081439A1 - AIRCRAFT ELEMENT HAVING A LEADING EDGE HAVING A SYSTEM FOR PREVENTING THE BLOCKING OF HOLES MADE IN THE LEADING EDGE - Google Patents

Abstract

The invention relates to an element comprising a leading edge forming a box (50) delimited by a skin (202) constituting a lower surface and an extrados and pierced with holes (205), where the skin (202) has an inner wall ( 202a) and an electrically conductive outer wall (202b) and an electrically insulating intermediate wall (202c), a pump for sucking or injecting air into the box (50). Each hole (205) is equipped with an anti-clogging system (350) which comprises a conductive base (354) and in electrical continuity with the inner wall (202a), a needle (358) made of piezoelectric material of which one end is integral. of the base (354), an electric generator (210) generating an electric current in the needle (358), wherein the shape of the needle (358) is such that a space (360) is created between the needle (358) and the edges of the hole (205), and wherein the base (354) has a recess (362) in the extension of the space (360). Such an installation makes it possible to eliminate the residues which are housed in the holes.

Description

AIRCRAFT ELEMENT HAVING A LEADING EDGE HAVING A SYSTEM FOR PREVENTING THE CLOGGING OF HOLES MADE IN THE LEADING EDGE

TECHNICAL AREA

The present invention relates to an aircraft element, such as for example a wing, said aircraft element comprising a leading edge and a system for preventing the filling of holes made in the leading edge, as well as an aircraft comprising at least one such aircraft component.

STATE OF THE PRIOR ART

An aircraft wing has a leading edge which is the front part of the aerodynamic profile constituting the wing. To ensure laminar flow along the leading edge, it is known to pierce the leading edge with a multitude of holes, conventionally 50 μm in diameter in a sheet of approximately 0.4 to 1 millimeter thick , to draw outside air from inside the wing through these holes or to expel air from inside the wing to the outside.

This leading edge is also often subject to the deposit of organic residues, these holes can be obstructed by these residues and they can no longer properly fulfill their function and the flow of air is therefore no longer laminar. but turbulent.

STATEMENT OF THE INVENTION

An object of the present invention is to provide an aircraft element comprising a leading edge which is pierced with a multitude of holes and equipped with a system making it possible to remove the organic deposits which are lodged in the holes.

To this end, an element of an aircraft is proposed, said element comprising:

- a leading edge forming a box delimited by a wall and a skin constituting a lower surface and an upper surface of the element and pierced with holes, where the wall connects an inner face of the lower surface to an inner face of the upper surface , where the skin has an electrically conductive inner wall, an electrically conductive outer wall and an intermediate wall disposed between the inner wall and the outer wall and being electrically insulating,

- a pump intended to draw the air present in the box and / or to inject air into the box, said element being characterized in that each hole is equipped with an anti-clogging system which comprises:

- an electrically conductive base and in electrical continuity with the interior wall,

- a needle made of a piezoelectric material, and housed in the hole and one end of which is secured to the base,

- an electric generator intended to generate an electric current in the needle, where the shape of the needle is such that a space is created between the needle and the edges of the hole, and where the base has a recess in the extension from space.

Such an installation makes it possible to eliminate the residues which are housed in the holes.

Advantageously, the electric generator is electrically connected between the interior wall and the exterior wall.

According to a particular embodiment, the anti-clogging system comprises an electrically conductive cap and surrounding the free end of the needle.

According to a particular embodiment, the anti-clogging system comprises an electrically conductive insert and inserted into the free end of the needle.

According to a particular embodiment, the needle and the cap, when present, each have the shape of a cylinder whose diameter is the diameter of the hole and have at least one flat over the entire height, and in this that each flat extends on the base to form the recess.

According to a particular embodiment, the needle and the cap, when present, each have the shape of a cylinder whose diameter is less than the diameter of the hole and which is coaxial with the hole.

The invention also provides an aircraft comprising at least one element according to one of the preceding variants.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the accompanying drawings, among which:

Fig. 1 shows a top view of an aircraft according to the invention, FIG. 2 shows a side view in section along line II-II of a leading edge of a wing of FIG. 1, FIG. 3 shows an enlargement of detail III of FIG. 2 in a first position of a needle according to a first embodiment of the invention, FIG. 4 shows an enlargement of detail III of FIG. 2 in a second position of a needle, FIG. 5 shows a perspective view of a needle according to a first embodiment of the invention, FIG. 6 shows a top view of the needle of FIG. 5 in the use position, FIG. 7 shows an enlargement of detail III of FIG. 2 in the first position of the needle according to a second embodiment of the invention, FIG. 8 shows a perspective view of a needle according to a third embodiment of the invention, FIG. 9 shows an enlargement of detail III of FIG. 2 in the first position of the needle according to the third embodiment of the invention, and FIG. 10 shows a top view of the needle of FIG. 8 in use position.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1 shows an aircraft 10 which has a fuselage 12 on either side of which is fixed a wing 100 which has a main part 103 and a leading edge 102 which extends above and below the wing 100 in front of the main part 103. The reference 104 shows a leading edge line which is the dividing line between the lower surface and the upper surface of the leading edge 102.

Fig. 2 shows the leading edge 102 in section. The leading edge 102 takes the form of a box 50 which is delimited by a skin 202 and a wall 203. The skin 202 constitutes a lower surface and an upper surface of the wing 100, that is to say that it takes the form of a U open towards the rear of the aircraft 10. The skin 202 has an outer face on which the air flows and an inner face oriented towards the inside of the leading edge 102 and the wall 203 connects the inner face of the lower surface to the inner face of the upper surface.

The skin 202 is pierced with a multitude of holes 205 which ensure the passage of outside air towards the inside of the box 50 and vice versa.

In order to ensure a suction of air from the outside through the holes 205 or a discharge of air to the outside through the holes 205, the wing 100 is equipped with a pump 207 which is provided to suck the air present in the box 50 and / or to inject air into the box 50. Here, the pump 207 is connected to the inside of the box 50 by a pipe 209.

Each hole 205 is equipped with an anti-clogging system 204 and preferably has a diameter of around 750 μm.

Figs. 3 to 6 show an anti-clogging system 350 according to a first embodiment of the invention, FIG. 7 shows an anti-clogging system 750 according to a second embodiment of the invention, and Figs. 8 to 10 show an anti-clogging system 850 according to a third embodiment of the invention.

In each of the embodiments, the skin 202 comprises an interior wall 202a, an exterior wall 202b and an intermediate wall 202c.

The inner wall 202a is oriented towards the inside of the leading edge 102 and therefore here towards the inside of the box 50. The inner wall 202a is electrically conductive. One of the faces of the interior wall 202a forms the interior face of the skin 202.

The outer wall 202b is oriented towards the outside of the leading edge 102 and is in contact with the air which flows around the leading edge 102. The outer wall 202b is electrically conductive. One of the faces of the outer wall 202b forms the outer face of the skin 202.

The intermediate wall 202c is disposed between the interior wall 202a and the exterior wall 202b. The intermediate wall 202c is electrically insulating and forms a dielectric.

Each hole 205 passes through the inner wall 202a, the outer wall 202b and the intermediate wall 202c.

In each embodiment of the invention, the anti-clogging system 350, 750, 850 comprises, for each hole 205 whose clogging must be avoided, a needle 358, 758, 858 housed in the hole 205.

The anti-clogging system 350 comprises for each needle 358, 758, 858, a base 354, 754, 854 secured to one end of the needle 358, 758, 858. The base 354, 754, 854 is electrically conductive and is in electrical continuity with the interior wall 202a. Electrical continuity is achieved for example by welding the base 354, 754, 854 to the interior wall 202a. In the various embodiments of the invention presented here, the base 354, 754, 854 has a wider part than the hole 205 and thus forms a rim which comes to bear against the face of the internal wall 202a which is oriented towards inside.

The needle 358, 758, 858 has a distal end which forms the free end 356, 756, 856 of the needle 358, 758, 858 and which is positioned opposite the external wall 202b.

The shape of the needle 358, 758, 858 is such that a space 360, 760, 860 is created between the needle 358, 758, 858 and the edges of the hole 205 in order to allow the passage of the blown air. or sucked by the pump 207. In the same way, the base 354, 754, 854 is shaped to leave a free space which extends the space 360, 760, 860. The base 354, 754, 854 thus has a recess 362, 762, 862 in the extension of space 360, 760, 860.

The needle 358, 758, 858 is made of a piezoelectric material which deforms when an electric current passes through it.

The needle 358, 758, 858 is such that, depending on the intensity of the electric current which passes through it, shortens or lengthens.

The anti-clogging system 350, 750, 850 also includes an electric generator 210 intended to generate an alternating electric current in the needle 358, 758, 858.

As shown in Figs. 3 and 4, when a first intensity (Fig. 3) is applied to the needle 358, it shortens and when a second intensity (Fig. 4) is applied to the needle 358, this s 'elongate. Thus, if residues are housed in hole 205, the back and forth movement of needle 358 will take off and dislodge the residues. The operation is identical for all the embodiments.

The current can be applied between the base 354, 754, 854 and the needle 358, 758, 858 and in particular its free end 356, 756, 856.

However, in order to apply the current to all of the needles 354, 754, 854 simultaneously, the current is applied between the interior wall 202a and the exterior wall 202b. As these two walls 202a-b are isolated from one another, the current will pass through each needle 358, 758, 858 from its free end 356, 756, 856 and the associated base 354, 754, 854. The electric generator 210 is therefore electrically connected between the interior wall 202a and the exterior wall 202b.

The free end 356 of the needle 358 may be bare, but as shown for the first embodiment of the invention shown in Figs. 3 to 6, the anti-clogging system 350 comprises an electrically conductive cap 364 and surrounding the free end 356 of the needle 358 in order to facilitate the passage of current between the outer wall 202b and the needle 358.

In the first embodiment of the invention, the needle 358 and the cap 364, when present, each have the shape of a cylinder whose diameter is the diameter of the hole 205 in order to ensure contact and have at least one flat 366 over the entire height to ensure the passage of air. Here, there are four flats 366 distributed regularly around the needle 358.

Each flat 366 forms the space 360 and each flat 366 extends on the base 354 to form the recess 362. The maximum distance between the flat 366 and the edge of the hole 205 is preferably around 50 μm.

In the second embodiment of the invention shown in FIG. 7, the anti-clogging system 750 comprises an insert 764 which is electrically conductive and inserted into the free end 756 of the needle 758. The insert 764 is flush with the surface of the free end 756.

In the second embodiment of the invention presented here, the needle 758 and the base 754 take the same shapes as those of the needle 358 and the base 354 of the first embodiment. When the electric generator 210 is activated, the electric current will transfer at the free end 756 either by electric arc at the space 760 thus generating a plasma effect which helps to destroy the residues present, or by conductivity between the needle 758 and the outer wall 202b.

In the third embodiment of the invention shown in Figs. 8 to 10, the needle 858 takes the form of a cylinder whose diameter is less than the diameter of the hole 205 and which is coaxial with the hole 205. The difference in diameter creates the space 860 and is preferably of the order from lOOpm.

When the electric generator 210 is activated, the electric current will be transferred to the free end 856 by an electric arc at the space 860, thereby generating a plasma effect which helps destroy the residues present.

In this third embodiment, it is also possible to provide for the installation of an electrically conductive cap surrounding the free end 856 of the needle 858, or an electrically conductive insert inserted in the free end. 856 of needle 858.

Preferably, the face of the anti-clogging system 350, 750, 850 which is at the level of the external face of the skin 202, that is to say the face of the free end 356, 756, 856 of the needle 358, 758, 858 or of the cap 364 when it is present and of the insert 764 when it is present is flush with said outer face of the skin 202 when no current is applied in order to ensure an aerodynamic surface.

An example of manufacturing a wing 100 comprising an anti-clogging system 350, 750, 850 according to the invention, consists in piercing the skin 202 using a drill in order to make the hole 205, for example having a diameter of 0.75 mm H7.

The anti-clogging system 350, 750, 850 is introduced into the hole 205 from the inside by bringing the base 354, 754, 854 against the interior wall 202a and fixing it by welding for example.

In the first embodiment and the second embodiment, the diameter of the needle 358, 758 and of the cap 364 when it exists is for example 0.75 mm g6.

In the first embodiment, the length of the needle 358 or of the cap 364 when it exists, is such that the end of the needle 358 or of the cap 364 protrudes beyond the outer surface of the skin 202 The end is then ground to come flush with the exterior surface of the skin 202.

In the second embodiment of the invention, the lengths of the needle 758 and of the insert 764 are such that the ends of the needle 358 and of the insert 764 protrude beyond the exterior surface of the skin 202. The ends are then ground to come flush with the outer surface of the skin 202.

In the third embodiment, the diameter of the needle 858 is for example 0.65 mm.

In the third embodiment, the length of the needle 858 is such that the end of the needle 858 protrudes beyond the outer surface of the skin 202. The end is then ground to be flush with the outer surface of the skin 202.

Although the invention has been described more particularly in the case of a wing, it applies in the same way to any element of an aircraft having a leading edge, such as for example a fin, a stabilizer, a air intake of an engine or a driving nacelle.

Claims (9)

1) Element (100) of an aircraft (10), said element (100) comprising: - a leading edge (102) forming a box (50) delimited by a wall (203) and a skin (202) constituting a lower surface and an upper surface of the element (100) and pierced with holes (205), where the wall (203) connects an inner face of the lower surface to an inner face of the upper surface, where the skin (202) has an electrically conductive inner wall (202a), an electrically conductive outer wall (202b) and an intermediate wall (202c) disposed between the interior wall (202a) and the exterior wall (202b) and being electrically insulating, - A pump (207) designed to suck the air present in the box (50) and / or to inject air into the box (50), said element (100) being characterized in that each hole (205) is equipped with an anti-clogging system (350, 750, 850) which includes: - a base (354, 754, 854) electrically conductive and in electrical continuity with the interior wall (202a), - a needle (358, 758, 858) made of a piezoelectric material, and housed in the hole (205) and one end of which is integral with the base (354, 754, 854), an electric generator (210) intended to generate an electric current in the needle (358, 758, 8528), where the shape of the needle (358, 758, 858) is such that a space (360, 760, 860) is created between the needle (358, 758, 858) and the edges of the hole (205), and where the base (354, 754, 854) has a recess (362, 762, 862) in the extension of the space (360, 760, 860). 2) Element (100) according to claim 1, characterized in that the electric generator (210) is electrically connected between the inner wall (202a) and the outer wall (202b). 3) Element (100) according to one of claims 1 or 2, characterized in that the anti-clogging system (350) comprises a cap (364) electrically conductive and surrounding the free end (356) of the needle ( 358). 4) Element (100) according to one of claims 1 or 2, characterized in that the anti-clogging system (750) comprises an insert (764) electrically conductive and inserted in the free end (756) of the needle (758). 5) element (100) according to one of the preceding claims, characterized in that the needle (358) has the shape of a cylinder whose diameter is the diameter of the hole (205) and has at least one flat (366 ) over the entire height, and in that each flat (366) is extended on the base (354) to form the recess (362). 6) element (100) according to claim 3, characterized in that the needle (358) and the cap (364) each have the shape of a cylinder whose diameter is the diameter of the hole (205) and have at least a flat (366) over the entire height, and in that each flat (366) extends on the base (354) to form the recess (362). 7) element (100) according to one of claims 1 to 4, characterized in that the needle (858) has the shape of a cylinder whose diameter is less than the diameter of the hole (205) and which is coaxial with the hole (205). 8) element (100) according to claim 3, characterized in that the needle (858) and the cap each have the shape of a cylinder whose diameter is less than the diameter of the hole (205) and which is coaxial with the hole (205). 9) Aircraft (10) comprising at least one element (100) according to one of the preceding claims.